Industrial trucks, carriers, movers and lifts of all sort have been adapted to have removably engaged therewith or removably mounted thereon the widest variety of working or lifting attachments. These include, without limitation, and only as a suggestion of the multiplicity of variety of such working attachments: carton clamps, pushers and push/pulls, load clamps, rotators, including those up to 360 degrees, fork positioners, side shifters, paper roll clamps, drum handlers and the like. Additionally, reach attachments, box dumpers, booms, car breakouts and the like may be added to this list.
For these many and varied working attachments, a number of mountings and quick attach/detachment arrangements have been provided. These devices typically involve the laterally sliding on and off of the working attachment with respect to normally horizontal carrier beams or a hook-over arrangement involving snap locks. In most cases, either the working operator must get off the vehicle and effect a sliding of the attachment on or off carrier beams or an intricate extendable and retractible coupler means has to be provided to permit the required engagement and disengagement.
It would be most useful to provide a quick couple construction for a vehicle which is readily and securely engageable with the work attachment and readily disengageable therefrom, but which does not require an extendable and retractible complex coupling means on the front of the vehicle, or does not require the individual operator to dismount to remove the attachment from the couple by sliding disengagement. Yet further, it is important to provide, in any vertical lift system, a minimum spacing or distance between the work attachment engaged and the couple for center of gravity and work space purposes. Still further, in most vertical lift systems, including those involving a multisegment mast arrangement, the provision of the couple-attachment engagement at or behind the contacting areas of the couple and work attachment would be a great advantage and improvement, not only with respect to space in storage, handling and work, but also with respect to security of engagement and optimum positioning of the center of gravity with respect to the lift system and mast or axis of lift.
What is basically desirous, and is not provided by the prior art, is a couple in a vertical lift system, the vertical lift system either static or mobile, where the engagement with the work member is behind the abutment interface of the lift element contacting the work attachment and the rear or abutting face of the work attachment. When a mobile system of this sort is provided, so long as the couple engagement zones are lower than the attachment engagement areas, the vehicle may be driven up to the work attachment, which is positively engaged by the couple simply by lifting a portion of the vertical lift system and without any requirement on the operator of leaving the driver's seat. In changing attachments again, the vehicle merely needs to be driven to the desired storage zone, the attachment lowered to the ground and, thereafter, the couple engagement members lowered below the level of the engagement means on the attachment. This type of disengagement permits the vehicle to back away and freely move to the next working attachment for engagement therewith.